B1556

DTC Troubleshooting: B1556

DTC B1556:

Automatic Lighting Control Unit Lost Communication With MICU (MICU Message)

Touring model

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Check for DTCs with the HDS.

Are DTCs B1055, B1106, B1157, B1255, B1355, B1556, B1806, B1955, B2005, and B2055 indicated?

YES -

Go to MICU input test MICU Input Test.�

NO -

Go to step 4.

4. Measure the voltage between automatic lighting control unit 14P connector terminals No. 1 and No. 8, and terminals No. 7 and No. 9 respectively.





Is there battery voltage?

YES -

Faulty automatic lighting control unit.�

NO -

Repair an open in the wire, a blown No. 30 (10 A) fuse or No. 21 (7.5 A) fuse in the driver's under-dash fuse/relay box, or poor ground (G501) or an open in the ground wire.�